Responses of Carbon Onions to High Energy Heavy Ion Irradiation
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Responses of Carbon Onions to High Energy Heavy Ion Irradiation Raed A. Alduhaileb,1 Kan Xie,1 Joshua C. Myers,1 Virginia M. Ayres,1 Benjamin W. Jacobs,1 Kaylee McElroy,1 T. Bieler,1 M. Crimp,1 Xudong Fan,2 Reginald M. Ronningen,3 Albert F. Zeller,3 Thomas Baumann,3 Atsushi Hirata4 1 College of Engineering, 2Center for Advanced Microscopy, and 3National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, U.S.A. 4 Graduate School of Mechanical Sciences, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan ABSTRACT We report evidence for graphene layer rearrangements in heavy ion interactions with carbon onions at 140 MeV and 70 MeV per nucleon kinetic energies. Graphene layer rearrangements have been recently predicted in spherical and cylindrical multi-layer graphene systems. The implications of graphene layer rearrangement on the tribological performance of multi-layer nano-carbons in extreme environments are discussed. INTRODUCTION Nano-carbon materials including carbon onions [1], C60 [1], carbon nanotubes [2], and graphene [3] are under investigation as nano-property enabled solid lubricants that maintain performance in extreme environments. An extreme environment for lubricants exists whenever the following stressors are present, either singly or in combination: radiation, vacuum and thermal stress. Space satellites and particle colliders are examples of applications in which radiation, vacuum, and thermal stress can seriously degrade current state-of-the-art lubricant performance. Many well publicized failures, including stuck bolts on the Hubble Space Telescope that required space-walk intervention, or accelerated wear and failure of soft gold electrical contacts at the Large Hadron Collider, can be traced back to the failure of current state-of-the-art lubricants due to radiation, vacuum and thermal stress. The potential for nano-carbon materials is that, first, they demonstrate low friction coefficients in vacuum, where oil, grease [4] and graphite [5] solid lubricants can fail. The best vacuum tribological performances amongst the nano-carbon materials investigated by our group have been achieved with carbon onions (multiple layer concentric fullerene shells) and with multiwalled carbon nanotubes [1,2]. Single walled carbon nanotube and C60 films displayed evidence of aggregation, leading to film discontinuities and lubrication failure. Second, theoretical work indicates that nanocarbon materials have high tolerances for thermal stress [6,7]. Therefore, nano-carbons materials have great potential as solid lubricants in space and particle collider applications if they also display radiation resiliency. In the present work, the responses of multiwalled carbon nanotubes and carbon onions to heavy ion irradiation at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University were investigated. Heavy ions are a highly
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penetrating component of both the space and particle collider environments. The heavy ions used i
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